Missing lives from other players

Merebear

i had about 6 or 7 lives in my mail box from other players. I claimed one because I didn't want to use all of them at the time. When I checked back my mail box was empty and all of my extra lives gone. It's happened before, it's discouraging 

KingsPinn

It's not that bad, you still get a free life every 30 minutes right! Between alternating between this game and Candy I can balance my lives quite nicely. 

samsmom

That is still not an answer.  You give and send lives, right?  What's the point if they disappear?